This object reports whether the device's clock selection is set to revertive, automatically switching back to the original preferred clock source once it recovers from a failure, or non-revertive, staying on the alternate source even after the original recovers. It matters operationally because it determines whether an admin needs to manually switch back to a preferred, higher-quality clock source after a transient failure clears, or whether the device will do it automatically. If this reports non-revertive and a fiber cut briefly knocked out the primary timing reference, the device will keep running on its secondary source even after the fiber is restored, until someone manually forces a switch back.